Asphaltene-paraffin structural interactions. Effect on crude oil stability

The effect of asphaltene-paraffin complexes on crude oil stability, in term s of wax crystallization and asphaltene deposits solubility, was studied. T he influence of flocculated asphaltenes on the wax crystallization tendency of a paraffinic crude oil and on the effectiveness of a maleic anhydride c opolymer derivative paraffin inhibitor was evaluated by means of polarized light microscopy. it was demonstrated that flocculated asphaltenes provide wax crystallization sites whose presence interferes with the inhibitor crys tal modification mechanism. The existence of asphaltene-paraffin complexes was assessed by, HPLC kinetic dissolution studies of composite materials fo rmed by combinations of such hydrocarbon fractions. Commercial macrocrystal line and microcrystalline waxes were used in these experiments. Different t ypes of asphaltenes were probed as well, covering varying ranges of aromati cities and stability. Asphaltene properties were observed to be important p arameters influencing composites dissolution. A selective partition of para ffins and asphaltenes in solubilized fractions was determined by high-tempe rature thin-layer chromatography.